Oil refining faces a fundamental contradiction: high temperatures remove harmful substances such as GE and 3-MCPD more thoroughly, but the same high temperatures also destroy heat-sensitive micronutrients including tocotrienols and carotenoids.

This is not an "either-or" choice, but an engineering challenge that requires optimized process conditions to achieve both goals.

Ocean's edible oil refining solution is to lower deodorization temperatures and apply improved refining controls, effectively meeting safety standards while maximizing the retention of natural nutrients.

1. Dual Objectives: Safety and Nutrition

Safety Target:

· Reduce the formation of glycidyl esters (GE)

· Reduce 3-MCPD content

· Control trans fatty acid (TFA) increase

These substances are heat-induced byproducts of the deodorization process and must be controlled to meet export standards for high-end markets such as the EU.

Nutritional Target:

· Retain tocotrienols — members of the vitamin E family with stronger antioxidant activity

· Retain carotenoids — natural pigments and antioxidant precursors

· Protect other heat-sensitive micronutrients

These nutrients are highly temperature-sensitive. Conventional high-temperature refining (240–260°C) causes significant loss, reducing the nutritional value and market competitiveness of the oil.

2. Core Strategy: Lower Deodorization Temperatures

The core strategy to achieve both objectives is: lower deodorization temperatures, combined with improved process controls to compensate for any potential reduction in deodorization efficiency.

Technical Approach:

Validation Results:

Under low-temperature deodorization conditions (180–220°C), combined with high vacuum (≤2 mbar) and optimized stripping design, Ocean's refining lines achieve:

· GE and 3-MCPD meeting EU standards (EU 2018/290)

· Significantly higher retention of tocotrienols and carotenoids compared to conventional high-temperature processes

· All finished oil specifications (acid value, smoke point, peroxide value) meeting quality standards

3. Nutrient Protection Strategies Across Refining Steps

Deodorization — The Most Critical Control Step:

Deodorization operates at the highest temperatures and has the greatest impact on nutrients, while also directly determining GE, 3-MCPD, and TFA formation. Ocean's dual-tower dual-temperature segmented deodorization technology decouples the thermal process:

· First stage (180–200°C): Removes light odor components and most FFA

· Second stage (210–220°C): Removes color precursors and more thermally stable odor compounds

This design achieves deodorization effectiveness while minimizing damage to heat-sensitive nutrients.

4. Processing Challenges to Address

Challenge 1: Balancing Refining Efficiency with Nutrient Retention

The lower the deodorization temperature, the lower the removal efficiency of FFA and odor compounds. How to ensure deodorization effectiveness at lower temperatures?

Ocean's Solution:

· Stable high vacuum (≤2 mbar) to lower vaporization temperatures of volatile compounds

· Increased steam-oil contact area (structured packing + tray combination)

· Precise temperature curve control to avoid excessive heating

Challenge 2: Balancing Safety and Nutritional Retention

Lower temperatures protect nutrients, but if temperatures are too low, GE and 3-MCPD removal efficiency may also decrease. How to meet both safety standards and nutritional retention goals?

Ocean's Solution:

· Dual-tower dual-temperature design completely avoids the >230°C GE/3-MCPD sensitive zone

· Upstream process optimization (reducing precursors in degumming and bleaching)

· Actual production line validation: GE ≤1.0 mg/kg, 3-MCPD ≤1.0 mg/kg with significantly improved micronutrient retention

Challenge 3: Precise Control of Process Conditions

Low-temperature deodorization requires higher precision in parameters such as vacuum, temperature, residence time, and stripping steam quantity. How to achieve stable and controllable production?

Ocean's Solution:

· Fully automatic PLC/DCS control system

· Multi-point temperature monitoring and real-time adjustment

· Multiple pre-programmed process curves for rapid switching between different oil types

5. Conclusion

Oil refining does not require choosing between "safety" and "nutrition."

With over 200 refining lines delivered across more than 20 years, Ocean has consistently demonstrated that safety and nutrition are not trade-offs — they can be achieved together. By lowering deodorization temperatures, increasing vacuum, shortening residence time, and adopting segmented design, Ocean's solution achieves:

· Safety: GE ≤1.0 mg/kg, 3-MCPD ≤1.25 mg/kg, TFA increase ≤0.5%

· Nutrition: Significantly improved retention of heat-sensitive micronutrients including tocotrienols and carotenoids

For refiners targeting export markets, this is a proven path to meet both goals.

Learn more about our edible oil refining production line .